Том 121, № 3 (2017)

The method of routine control of the power release in the VVER-1000 reactor using the offset-cardinality phase diagram is examined. This method minimizes the changes in the local power release accompanying a change in the running values of the reactor power and the axial offset, characterizing the unevenness of the power distribution over the core height. The results of computational validation of the method are presented. The rules for using offset-cardinality diagrams for operating units of VVER-1000 are presented.

A model of a passive autocatalytic hydrogen recombiner (RVK-500, -1000) for use in hydrodynamic calculations of hydrogen transport and recombination processes in a VVER containment shell during a severe accident is described. The model includes calculation of the efficiency of the recombiner, the hydraulic resistance to gas flow through the recombiner, and heat losses owing to radiation from the casing of the recombiner. The model was parameterized and verified on experiments performed on a stand at VTI and INPK RET for hydrogen-air compositions with hydrogen volume fraction up to 10%. Good agreement was obtained between the calculations and experiments. Its simplicity and efficacy make it possible to use the model in hydrodynamic calculations of processes with recombiners in a real containment shell.

The results of testing the CONV-3D code and methods of direct numerical modeling, using supercomputers, of turbulent flows in the elements of nuclear power plants are presented for problems as close as possible to real processes: natural and forced convection of sodium in the upper plenums of the Monju nuclear power plant in Japan and mixing of the two flows at different temperatures in the secondary loop of the Phénix reactor in France. The particularities of the method for calculating the thermo- and hydrodynamic characteristics of the equipment in nuclear power plants are listed.

Experimental studies of the hydrolysis of sodium beryllate, which plays an important role in the production of beryllium hydroxide, are expounded. The influence of the caustic modulus on the completeness of beryllium extraction into hydroxide and the decomposition kinetics of sodium beryllate are studied. The parameters of hydrolysis in application to alkali solutions of autoclave breakdown of beryllium-containing concentrate are presented. It is shown that aluminum can be efficiently separated from beryllium during hydrolysis of sodium beryllate.

The results of a study of the present-day motions of the Earth’s crust, using GPS/GLONASS satellite systems, within the Nizhnekansk massif (Krasnoyarsk krai), where the construction of an underground repository for the disposal of high-level radioactive wastes is planned. Observations conducted in 2010–2014 have provided new information about the regime of present-day motions at the junction of the largest tectonic structures region – the Siberian platform and West Siberian plate as unified parts having deep geodynamic force sources. On the whole, no anomalous values of present-day motions of the Earth’s crust, suggesting the presence of tectonic instability of the geological environment, have been recorded.

The aim of this work is to validate the extraction parameters of fission products and actinides from the spent nuclear reactor fuel of the BREST-OD-300 reactor on the basis of the concept of radio-ecological balance. The dose loads due to long-lived high-level wastes and natural uranium are compared for humans. Different variants of extraction of fissile materials U, Pu, and Np from spent fuel with residual content in the wastes 0.1–1% of the initial content and americium with residual content in the wastes 0.1–10% of the initial content with decay period of the spent fuel in the range 1–100 years were taken as initial data. It was found that for the indicated variants of reprocessing it is impossible to achieve radioecological balance for humans after 500 years without extracting ⁹⁹Tc with residual content in the wastes not exceeding 5% of the initial content in the spent fuel. The time to achieve balance can be reduced to 300 years with additional extraction of ¹³⁷Cs.

The informative parameters of microwave signals making it possible for distinguish by means of passive radiolocation a nuclear explosion in the atmosphere among other sources of microwave radiation (lightning or accident at NPP) and to evaluate the power and altitude of the explosion are discussed. The wavelengths falling within the atmospheric transparency range from several millimeters to tens of centimeters are examined.